Virtualization may allow one physical server or group of servers to accomplish many tasks that may be usually dedicated to many different servers. A separate instance, or “virtual machine,” may be created for a task. For example, a separate virtual machine may be created to function as a web server, and a separate virtual machine may be created to function as an e-mail server. Each of the virtual machines, however, may operate on the same physical server or group of servers, and may have access to the same storage pool. Consolidation may allow for decreased ownership and maintenance cost and may increase efficiency in administration and management.
Virtual machines may be linked to storage space. For example, a virtual machine may require access to one or more hard disk drives or magnetic or optical storage options. Storage space may be stored within one or more storage pools, which may be physical servers having access to a network.
A physical server may be removed from operation for many reasons. For example, a physical server may be taken off-line for maintenance, or a physical server may be upgraded or replaced. Additional physical servers may be added to a server pool to increase the overall capacity and resources of the server pool. Also, physical servers may be removed from a server pool to decrease the overall capacity of the server pool. Additionally, storage pools may be created or removed from a server pool for similar reasons.
A virtual machine may be moved from one physical server to another physical server. Storage space for a virtual machine may also be moved from one storage pool to another storage pool. It may be beneficial to move a virtual machine from one physical server to another physical server and/or move a storage area from one storage pool to another storage pool in a way that maximizes the ability of the virtual machine to accept additional instructions or requests.
Moving a virtual machine from one physical server to another may require copying memory of the virtual machine from one physical server to another physical server. Moving a storage area from one storage pool to another storage pool may take the virtual machine off-line while the storage area is copied.
In an environment that requires or desires high availability, moving storage areas associated with virtual machines by halting the virtual machine, moving the storage area, and restarting the virtual machine may be undesirable. A better solution may allow the virtual machine to continue to operate, with minimum or no impact, while the storage area is moved. By minimizing downtime, high availability may continue to be achieved.
In view of the foregoing, it may be understood that there are significant problems and shortcomings associated with current storage area migration technologies.